The proposed study is directed toward a comparison of collagen metabolism in healthy and in inflammed gingiva during the course of inflammatory periodontitis. Specifically, collagen synthesis in normal and diseased gingiva will be studied using biochemical probes to determine (1) total content of collagen in gingiva during the progress of the disease; (2) the maturational state of collagen in diseased tissues by comparing the solubility distribution of collagen into salt-soluble, acid-soluble, and insoluble fractions in inflammed and healthy gingiva; and (3) the rate of collagen synthesis relative to total protein synthesis in diseased versus healthy tissues. The characterization studies (#1 and #2) will be based on a systematic analysis of the content of hydroxyproline in the tissues and its solubility distribution. The relative rate studies (#3) will be performed by labelling gingival tissues in vitro with 3H-proline and digesting the labelled proteins with protease-free bacterial collagenase to separate collagen and non-collagen proteins. Rates of collagen vs non-collagen protein synthesis will be determined from the kinetics of 3H-proline incorporation into each moiety. The relationship between collagen content, collagen solubility, and rate of synthesis during the progress of inflammatory periodontitis will allow an assessment of whether an impairment in collagen synthesis and/or maturation contribute to the loss of collagenous structures during the course of the disease.